A property-value pair representing an additional characteristics of the entitity, e.g. a product feature or another characteristic for which there is no matching property in schema.org.

Note: Publishers should be aware that applications designed to use specific schema.org properties (e.g. http://schema.org/width, http://schema.org/color, http://schema.org/gtin13, ...) will typically expect such data to be provided using those properties, rather than using the generic property/value mechanism.

The value of the quantitative value or property value node. For QuantitativeValue, the recommended type for values is 'Number'. For PropertyValue, it can be 'Text;', 'Number', 'Boolean', or 'StructuredValue'.

An additional type for the item, typically used for adding more specific types from external vocabularies in microdata syntax. This is a relationship between something and a class that the thing is in. In RDFa syntax, it is better to use the native RDFa syntax - the 'typeof' attribute - for multiple types. Schema.org tools may have only weaker understanding of extra types, in particular those defined externally.

Indicates a page (or other CreativeWork) for which this thing is the main entity being described.

Many (but not all) pages have a fairly clear primary topic, some entity or thing that the page describes. For
example a restaurant's home page might be primarily about that Restaurant, or an event listing page might
represent a single event. The mainEntity and mainEntityOfPage properties allow you to explicitly express the relationship
between the page and the primary entity.

Related properties include sameAs, about, and url.

The sameAs and url properties are both similar to mainEntityOfPage. The url property should be reserved to refer to more
official or authoritative web pages, such as the item’s official website. The sameAs property also relates a thing
to a page that indirectly identifies it. Whereas sameAs emphasises well known pages, the mainEntityOfPage property
serves more to clarify which of several entities is the main one for that page.

mainEntityOfPage can be used for any page, including those not recognized as authoritative for that entity. For example,
for a product, sameAs might refer to a page on the manufacturer’s official site with specs for the product, while
mainEntityOfPage might be used on pages within various retailers’ sites giving details for the same product.

about is similar to mainEntity, with two key differences. First, about can refer to multiple entities/topics,
while mainEntity should be used for only the primary one. Second, some pages have a primary entity that itself
describes some other entity. For example, one web page may display a news article about a particular person.
Another page may display a product review for a particular product. In these cases, mainEntity for the pages
should refer to the news article or review, respectively, while about would more properly refer to the person or product.
Inverse property: mainEntity.

The time needed to accelerate the vehicle from a given start velocity to a given target velocity.
Typical unit code(s): SEC for seconds
Note: There are unfortunately no standard unit codes for seconds/0..100 km/h or seconds/0..60 mph. Simply use "SEC" for seconds and indicate the velocities in the name of the QuantitativeValue, or use valueReference with a QuantitativeValue of 0..60 mph or 0..100 km/h to specify the reference speeds.

The available volume for cargo or luggage. For automobiles, this is usually the trunk volume.
Typical unit code(s): LTR for liters, FTQ for cubic foot/feet
Note: You can use minValue and maxValue to indicate ranges.

The interval and unit of measurement of ordering quantities for which the offer or price specification is valid. This allows e.g. specifying that a certain freight charge is valid only for a certain quantity.

The volume swept by all of the pistons inside the cylinders of an internal combustion engine in a single movement.
Typical unit code(s): CMQ for cubic centimeter, LTR for liters, INQ for cubic inches
Note 1: You can link to information about how the given value has been determined using the valueReference property.
Note 2: You can use minValue and maxValue to indicate ranges.

The power of the vehicle's engine.
Typical unit code(s): KWT for kilowatt, BHP for brake horsepower, N12 for metric horsepower (PS, with 1 PS = 735,49875 W)
Note 1: There are many different ways of measuring an engine's power. For an overview, see http://en.wikipedia.org/wiki/Horsepower#Engine_power_test_codes.
Note 2: You can link to information about how the given value has been determined using the valueReference property.
Note 3: You can use minValue and maxValue to indicate ranges.

The capacity of the fuel tank or in the case of electric cars, the battery. If there are multiple components for storage, this should indicate the total of all storage of the same type.
Typical unit code(s): LTR for liters, GLL of US gallons, GLI for UK / imperial gallons, AMH for ampere-hours (for electrical vehicles)

The amount of fuel consumed for traveling a particular distance or temporal duration with the given vehicle (e.g. liters per 100 km).
Note 1: There are unfortunately no standard unit codes for liters per 100 km.
Use unitText to indicate the unit of measurement, e.g. L/100 km.
Note 2: There are two ways of indicating the fuel consumption, fuelConsumption (e.g. 8 liters per 100 km) and fuelEfficiency (e.g. 30 miles per gallon). They are reciprocal.
Note 3: Often, the absolute value is useful only when related to driving speed ("at 80 km/h") or usage pattern ("city traffic"). You can use valueReference to link the value for the fuel consumption to another value.

The distance traveled per unit of fuel used; most commonly miles per gallon (mpg) or kilometers per liter (km/L).
Note 1: There are unfortunately no standard unit codes for miles per gallon or kilometers per liter.
Use unitText to indicate the unit of measurement, e.g. mpg or km/L.
Note 2: There are two ways of indicating the fuel consumption, fuelConsumption (e.g. 8 liters per 100 km) and fuelEfficiency (e.g. 30 miles per gallon). They are reciprocal.
Note 3: Often, the absolute value is useful only when related to driving speed ("at 80 km/h") or usage pattern ("city traffic"). You can use valueReference to link the value for the fuel economy to another value.

The permitted weight of passengers and cargo, EXCLUDING the weight of the empty vehicle.
Typical unit code(s): KGM for kilogram, LBR for pound
Note 1: Many databases specify the permitted TOTAL weight instead, which is the sum of weight and payload.
Note 2: You can indicate additional information in the name of the QuantitativeValue node.
Note 3: You may also link to a QualitativeValue node that provides additional information using valueReference.
Note 4: Note that you can use minValue and maxValue to indicate ranges.

The permitted total weight of cargo and installations (e.g. a roof rack) on top of the vehicle.
Typical unit code(s): KGM for kilogram, LBR for pound
Note 1: You can indicate additional information in the name of the QuantitativeValue node.
Note 2: You may also link to a QualitativeValue node that provides additional information using valueReference.
Note 3: Note that you can use minValue and maxValue to indicate ranges.

The speed range of the vehicle. If the vehicle is powered by an engine, the upper limit of the speed range (indicated by maxValue) should be the maximum speed achievable under regular conditions.
Typical unit code(s): KMH for km/h, HM for mile per hour (0.447 04 m/s), KNT for knot
Note 1: Use minValue and maxValue to indicate the range. Typically, the minimal value is zero.
Note 2: There are many different ways of measuring the speed range. You can link to information about how the given value has been determined using the valueReference property.

The permitted vertical load (TWR) of a trailer attached to the vehicle. Also referred to as Tongue Load Rating (TLR) or Vertical Load Rating (VLR).
Typical unit code(s): KGM for kilogram, LBR for pound
Note 1: You can indicate additional information in the name of the QuantitativeValue node.
Note 2: You may also link to a QualitativeValue node that provides additional information using valueReference.
Note 3: Note that you can use minValue and maxValue to indicate ranges.

The torque (turning force) of the vehicle's engine.
Typical unit code(s): NU for newton metre (N m), F17 for pound-force per foot, or F48 for pound-force per inch
Note 1: You can link to information about how the given value has been determined (e.g. reference RPM) using the valueReference property.
Note 2: You can use minValue and maxValue to indicate ranges.

The permitted weight of a trailer attached to the vehicle.
Typical unit code(s): KGM for kilogram, LBR for pound
Note 1: You can indicate additional information in the name of the QuantitativeValue node.
Note 2: You may also link to a QualitativeValue node that provides additional information using valueReference.
Note 3: Note that you can use minValue and maxValue to indicate ranges.

The permitted total weight of the loaded vehicle, including passengers and cargo and the weight of the empty vehicle.
Typical unit code(s): KGM for kilogram, LBR for pound
Note 1: You can indicate additional information in the name of the QuantitativeValue node.
Note 2: You may also link to a QualitativeValue node that provides additional information using valueReference.
Note 3: Note that you can use minValue and maxValue to indicate ranges.

Acknowledgements

This class is derived from the GoodRelations Vocabulary for E-Commerce, created by Martin Hepp. GoodRelations is a data model for sharing e-commerce data on the Web that can be expressed in a variety of syntaxes, including RDFa and HTML5 Microdata. More information about GoodRelations can be found at http://purl.org/goodrelations/.